Conventionally, a teleconference system has been provided as an example of a system for sharing videos and audio among a plurality of bases connected via a communication network. However, in the conventional system, there is a problem in that data output is often delayed, due to deterioration of the communication state of the communication network. When the data output is often delayed, the sound and image are intermitted, and the participants of the conference cannot properly obtain necessary information.
In this regard, Japanese Patent No. 5000141 (Patent Literature 1) discloses a method of preventing audio from being intermitted, by notifying a transmission terminal that a packet delay occurs in a reception terminal, and reducing the amount of data in the transmission packet excluding audio data in the transmission terminal.
However, the data output is delayed not only due to the transmission delay of the communication network, but in many cases, due to the internal processing delay (processing time period from when data is received to when an output signal is generated) at the data receiving side. Thus, the output delay may not be prevented by just focusing on the communication state of the communication network as in Patent Literature 1.